Jeff1964

Hi,

On my gs300 the brake pedal keeps going to the floor.

1st - I changed the brake pads in the rear, (they were a little low) the front pads are good and no fluid is leaking.

2nd - I blead the back brakes and got a good stream of fluid on both sides
I tried to bleed the front and only get a trickle. Still have no breaks.
anyone have a clue where I go next? Brakelines, Master cylinder, splitter valve, Bladder?

TheMole

iTrader: (13)

Seems like a bleeding issue. There is a certain way to bleed the brakes, but maybe someone else can confirm.

smalldog

Jeff1964 , did you figure out whats going on with your brakes? I'm having the same type of issues.

Carfreak70

iTrader: (16)

I'm having the same issue too! WTF is going on?

Yakshii

iTrader: (1)

lol bleed your brakes or bleed them better

JZSARISTO

If you bleed your brakes already and the problem persist then its your brake master cylinder.

ChrisH

Yeah you need to bleed your brakes, relatively easy with a friend. You might have air in your brake system , and air will simply compress when you push down the pedel, which may explain your problem. Good luck!

Carfreak70

iTrader: (16)

I am going to bump this back up and see if there is more information on what was going on. When I did my LS400 converison, I had EVERYTHING new. These were the problems I was having.

1. The brakes went on after I grinded the crap out of the caliper and modified suspension parts, but when the rotor was put on, the front wheels would spin 180* and then stop. I was finally able to lift the rotor until it fit perfectly. It was weird. Had a very sensitive sweet spot for some reason?
2. After the brakes were on with new pads and new everything the brakes WOULD NOT bleed. I had 100% all of the air out of the lines. I bled them for HOURS.
3. Uninstalled everything, and the brakes are working just fine stock. I have no CLUE what was going on...

Thats about all of the information I can provide. I just want to see if someone can shed some light,

Jussjoshin

Keep bleeding. Rr lr rf lf then master. If you still have issues your master may have an internal leak. Bleeding off back into itself. Sounds like bleeding to me though. If youre just getting a trickle then there's a blockage in the caliper.

Carfreak70

iTrader: (16)

It's not bleeding. That is for sure

Jussjoshin

It's a sealed system so there's only a few things that would cause a pedal to go soft or completely flat.

1.) air in the system
2.) a leak in the system
3.) wrong master. If you upgraded the calipers and what not then the master has to be able to push them.
4.)a faulty master. Bleeding back into itself
5.) air it the system or even.... Air in the system lol

Make sure u have the calipers on the right side. Bleeder screws facing up.
Start bleeding from the furthest point away and work your way to the master. Even crack the lines loose at the proportioning/metering valve if you have to. There's not a whole lot that can go wrong as its a simple system. If you have abs you might have air in the module but since you said they work fine with the stock parts I highly doubt that to be the case. If you installed a new master cylinder than you must bench bleed it before installing or it won't ever be right.

Jussjoshin

Why did you bleed the brakes if you just replaced pads? In the future, open the res cap and slowly compress the caliper piston back in. You don't need to open the hydraulic system. You need to keep bleeding the front till you have a good stream with NO air. If you can't bleed them you need to replace them

blackie76

One thing you want to do is first flush your brake fluid, then there is a certain order you have to follow when bleeding a lexus you have to look up that pattern. I think it goes...

REAR RIGHT WHEEL, REAR LEFT WHEEL, FRONT RIGHT WHEEL, FRONT LEFT WHEEL. TH FAR WHEEL IS ALWAYS FIRST AND THEN AS FOLLOWS.

Carfreak70

iTrader: (16)

You're correct, that is the right sequence. It is farthest from the master, to the master. I did that as well. I am pretty sure the master couldn't handle the extra 4 pistons..but I dont know. The master does have 330K on it lol

jtamulis

iTrader: (1)

master cyl